DYNAMIC ANALYSES OF SHORT CIRCUITING TRANSFER PROCESS IN CO2 ARC WELDING-DYNAMIC BEHAVIOUN OF SHORT CIRCUITING LIQUID BRIDGE AND ITS MECHANICAL MEASUREMENT
CO2焊接短路过渡过程的动态分析—短路液桥的动态变化与力学测算

CO2 arc welding is a kind of welding technology with high efficiency,economicenergy and low cost,It has been widely used in welding steel structures,but there existpro blems such as metal spatter,bad appearance of weld,etc.In order to resolve theseproblems,it is necessary to approach theoretically the arc characteretlcs and the behaviourof the droplets. In this paper,the all process of droplet growing,necking,dripping andcurrent-voltage waves responding to it during the shorting circuiting transfer in CO2 arcwelding was recorded synchron ously by high-speed photography and oscillogmphy, whichwere analysed by means of film data processing system to obtain the maximum currentaed the resultant force at the instant when the formed liquid metal bridge exploded duringthe droplet transfer.The mechanism of short circuiting transfer was further investigatedaed a model was establlshed It has important instructive meaning for adjusting the weldingparameters and ensuring the welding quality.It is concluded that in the normal CO2 arcwelding with short circuiting transfer the spatter controll is key to irnprove welding quality,aed the substantial means by which the spatter is in hibited is adjusting the short circuitingfrequency and the peak current through the change of welding conditions.